Abstract
The effect of delamination or cavitation of particles on the toughness of spherical and layered particulate composites is discussed using the Mori-Tanaka model. Both spherical and spheroidal particles are considered. The model is compared with other models reported in literature and shows fair agreement. In general, at the onset of delamination both stress and bulk modulus drop and this drop continues until delamination is complete. The debonding toughness increases with volume fraction but more effectively with particle aspect ratio. Rather surprising is the fact that the debonding toughness does not increase for high ratios of particle bulk modulus to matrix bulk modulus (>20). This may be a consequence of the sharp decrease in the composite bulk modulus as delamination progresses. The study shows marginal increase in toughness especially from debonding of spherical particles.